Control of Oil Droplet Migration Behavior and Friction Reduction Effect of SAMs Film under Temperature Gradient

Self-assembled monolayers (SAMs) and local ultraviolet lithography were used to prepare the wettable strip surface, which was used to solve the problem of oil starvation in the contact area caused by the thermocapillary migration of oil droplets due to the temperature gradient. Using a high speed camera and a contact angle measuring instrument, the migration speed, migration distance and contact angle of liquid paraffin on the prepared surface and the original stainless steel surface were compared under a temperature gradient. The results showed that the thermocapillary migration of oil droplets could be effectively inhibited by the stripe pattern designed on the stainless steel surface. In addition, friction and wear tests were then carried out on the prepared area, which showed that the prepared area was able to keep the liquid paraffin in the friction contact area during friction, which slowed down oil starvation in the contact areas and significantly reduced the friction and wear. This study provided a new idea and method for the solution of the problem of oil starvation in the contact area due to the thermocapillary migration of oil droplets.